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Patented] 8 1880, v

- W. A. SWEET. Steel Bars for Mining-Drill UNTTED STATES PATENT OFFICE.

WILLIAM A. SWEE'IE OF SYRACUSE, NEW YORK.

STEEL BAR FOR MINING-=DRILLS.

SPECIFICATION forming part. of Letters Patent N 0. 228,485, dated June 8, 1880.

Application filed December 20, 1879.

To all whom it may concern Be it known that I, WILLIAM A. SWEET, of Syracuse, Onondaga county, State of New York, have invented a new and Improved Formation of Steel Bars for Mining, Quarrying, and other Drills as an article of manufacture, of which the following is a specification.

Heretofore drills have been madefor the above purposes by laborious and expensive processes of forging from octagonal steel bars that produced drills less perfect than those made from the drill-steel made by me. I11 forging drills for the above purposes the process has been .to forge the end of the bar for an inch or so into the required form of a drill, leaving the rest of the bar in its original form, with a liability to clog not found in my improvement, and as the drill wears the portion is forged into form, involving much additional time and expense, which are saved by my device, which is formed throughout its entire length true in outline of proper configuration for the drill, and of a more homogeneous and perfect density than the forged drill, and gives afree and unobstructed clearance above the point.

The construction of my new and improved drill-steel produces a perfect and durable article, accurate in its cross-section, so that it can be worn up throughout its entire length without reforging. It is manufactured much more rapidly and cheaply than the drills heretofore made, and as an article of manufacture my drill-steel is more convenient, durable, and cheap than any heretofore produced for a like purpose, and works more freely.

My drill-steel for making drills, as above stated, consists of a blank rolled from a bar of steel into perfect form for a drill, as seen at Figure 1, without forging or swaging. A shows its cross-section with four wings. Figs. 2 and 3 are modifications, B and 0 being their modified sectional forms.

The steel bar, cut to proper length, is rolled into the form desired, ready, when taken in hand by the smith, to form a complete drill for use by adding a shank thereto, and, having the samecontour throughout its entire length, it can be used until it is worn up to the shank without any change of form.

To make this drill-steel I employ a set of rollers, (for which I am about to apply for Letters Patent,) through which I pass a properly-rolled steel bar, that in passing through said rollers is shaped into the form shown in the figures, and a piece thus formed is completed for a drill by affixing an iron shank thereto or forming it from the steel bar.

Having thus fully described my new and improved drill-steel, I claim- Rolled bars of steel of the shape herein described and shown as a new article of manufacture, designed for use in the manufacture of drills for mining and quarrying purposes.

IV. A. SWEET.

Witnesses:

OHAs. W. H. W001), J. WEED MUNRo. 

